""The big block setup isn’t near that complicated""

I started with a smaller plate (depth wise), but I ran out of adjustment with the 2 screws up top. So I moved the tool farther away from the springs (as shown) and it worked out much better. I then added the bolts to the bottom of the plate (resting on the head) just to give the plate some more support and not all of the load is on the two rocker shaft bolts. Once this was worked out, the spring swap was quick and easy.